The Suårangama Sutra: Looking into the roots of klesa

From the Suarangama Sutra, pg 150.
The point of departure 

Ananda, if you wish to bring your seeing, hearing, feeling and knowing into line with the Tathagataís absolute Eternity, Bliss, Self and Purity, you should first pick out the root of birth and death, and turn its worldly falseness back to its un- worldly profound nature until it is subdued and reverts to Basic Bodhi, and then use this pure nature as the causal mind-ground (i.e. as the point of departure) to perfect your practice and realization of the fruit-ground.

This is like purifying muddy water in a clean container; left unshaken in complete calmness, the sand and mud will sink to the bottom. When the clear water appears, this is called the first suppression of the intruding evil element of passion. When the mud has been removed leaving behind only the clear water, this is called the permanent cutting off of basic ignorance. Enlightenment is (pure and) unmixed; and its manifestations are not of the nature of kle ̃a, but are in accord with the immaculate virtues of Nirvana. Looking into the roots of klesa to find the sense organ suitable for meditation.

What is the second decisive factor? In your determination to develop the Bodhi Mind and to advance boldly along the Bodhisattva Path by relinquishing everything worldly, you should look closely into the origin of klesa, caused by your basic ignorance and developing discrimination, and see who .  Ananda, in your cultivation of Bodhi, if you do not inquire into the root of klesa, you will never know (how and) where the organs and sense data are turned upside down. If you fail to understand this, how can you overcome them to win the Tath‡gata stage ë‚nanda, if a man who is good at untying knots, does not see them, how can he undo them? And you have never heard that the void can be unfastened for it has neither form nor shape and is not like a knot that can be untied. But your eyes, ears, nose and tongue as well as your body and mind, are the six decoys which a thief uses to steal the treasures of your house. For this reason, since the time without beginning, living beings and this world, have always been interlocked (in time and space) hence you are unable to leap beyond the material world. Ananda, what is (this) realm of time and space?( Time means duration and space location.) You know that the ten directions are in space and that the past, present and future are in time. There are ten directions (of space) and three (aspects of) time. All living beings owe their bodies to illusory time and space which are interwoven within them and continue to affect them. Although there are ten directions, the worldly man recognizes only the east, west, south and north as cardinal points but disregards the intermediate ones and the zenith and nadir which he considers as unimportant.